Redarc bcdc1220

Put one of these in the tray last week Smart Start BCDC | Redarc Electronics . Seems to be working well so far as the aux batteries are getting to full charge alot easier. I think its around 20amp which is even better than my 240volt charger puts out. Anyone else using one of these?

yeah mate, i've had one in my tray charging a 100Ah Gel battery for about a month and a half now, it's a neat little machine, well worth the money i spent on it.

Ya there expensive but it gives the batts a great charge,no regrets from me.

Actually I do have regrets , they just brought out a new one that charges twice as quick as the one I just bought a few months ago! always bloody happens!

Quick charging isn't always a better option just because the manufacturers say they can do it.

Gel batteries particularly don't like being charged quickly, nor do they enjoy a high charge voltage. Anything much beyond 14.1V on the terminals is toast time for a gel and they do NOT recover, even if you have a C-Tek and do a "Recycle" charge on them. This only kils them faster by forming even more bubbles in the gel!

Some AGM batteries don't mind going fast in either direction. You can get 700+ CCA AGM spiral wound batteries that can be dropped to 20% of their capacity. Can't argue with their ruggedness, it's only their enormous cost that makes you think twice.

I'd argue that regular quick charging or quick draining of just about any battery is not good for the battery. Quick charging might be ok occasionally but as a regular or only option I wouldn't bother.

Some can handle it. Spiral wound AGMs were designed for military use, where fast charging was an important aspect - as well as ruggedness.

It really is important to follow the manufacturer's specs for each battery - because it isn't the forum - or its members - who are going to replace the battery when it dies on you!

Interesting comments.. I was under the impression that the BC-1220 and similar DC to DC chargers still charge at the 12 - 14volts but are able to increase current to the battery so that your alternator doesn't need to work so hard.?

i.e. I am installing a dual battery under the hood, and a dual battery in my camper trailer. So there will be two x BC 1220's taking up the current from the alternator and boosting it so all four batteries at least get some juice. Otherwise, they just wouldn't charge properly at all..

Considering I will be running two fridges I need as much power into them when the car is running as I can get..

That was my thoughts on the DC to DC chargers anyway.

I'm doing very similar, but I use inverters to produce 240V and then use "normal" smart chargers to bring the battery voltages back up.

Pumping current into a lead acid battery at a low voltage won't reverse the chemical reaction that produces electricity - all it will do is heat the battery up.

What's needed is a sufficient voltage (potential difference) to overcome the reaction and reverse it. Think of it like this - higher voltage = higher energy, higher current = more electrons. Current produces heat (eg arc welder) and voltage makes electrons move about (old tube-type TV sets, those archaic things called spark ignitions etc).

A typical lead acid battery won't fully charge in a short time unless its input voltage is around 14.7V. Gel batteries will die at that voltage (long term) as the mild fizzing produced above 14.1V forms little air bubbles in the jelly between the plates and that's the end of the line for the battery. Gels charge fully over a longer period of time and despite having one of my own, I no longer consider them viable as a camper battery because of their tendency to fail.

So, the controller must be boosting the voltage in order to charge the battery properly and the folks at Redarc would know to do this even better than I, or the sources that I commonly use to learn about this stuff - Collyn Rivers, Battery University and the C-Tek site.

It would be interesting to measure the output and make sure it's doing it right. If you have a gel in there, watch the voltage carefully and make sure that if the device has a "gel" option, you use it so that the charge voltage is limited.

KraftyPg said:

Quick charging isn't always a better option just because the manufacturers say they can do it.

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Yep, there is a seller of AGM batteries that tells people it can be "completely recharged in four hours" so people buy 40 Amp battery chargers and use them on their batteries.

What isn't pointed out to them that by doing this, instead of getting about 1,500 recharges,they are only going to get about 500 recharges before the battery is very liable to fail.

Tony in Tas said:

Interesting comments.. I was under the impression that the BC-1220 and similar DC to DC chargers still charge at the 12 - 14volts but are able to increase current to the battery so that your alternator doesn't need to work so hard.?

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Nope, doesn't magically create current. What it does do is boost the voltage coming in to the correct charging voltage for the type of battery it is doing. The only way it can do that is to "rob" current.

If the inputs to the charger areat 10V(wiring is far too thin) and it is getting 14.1Amps, or 141Watts, then the theorectical maximun it can actually out put is 10Amps at 14.1volts(correct battery charging voltage?) They are all about bringing the voltage being applied to the correct level.

In truth, they would just suck more current from the alternator(make it work harder). If it is available. So you are not going to get maximum possible charging if you have all the spotties running. Hint, if turning on an extra spotty dims the others, then your battery recharger is going to be getting less current that the battery needs.

i.e. I am installing a dual battery under the hood, and a dual battery in my camper trailer. So there will be two x BC 1220's taking up the current from the alternator and boosting it so all four batteries at least get some juice. Otherwise, they just wouldn't charge properly at all..

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If you have a voltage dependant isolator, your twin starter batteries will be "properly recharged first and only then should the alternator surplus be given to the BC1220's.

What is the capacity of your alternator? At full bore, they should only take 40 amps maximum (bulk stage)

Considering I will be running two fridges I need as much power into them when the car is running as I can get..

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What sort of fridge? Fridge or freezer?

Floating around are typical consumption figures for the various types of fridge/freezers. Easy to do some basic calcs and work out how long you need to drive for.

terryc said:

What is the capacity of your alternator? At full bore, they should only take 40 amps maximum (bulk stage)

What sort of fridge? Fridge or freezer?

Floating around are typical consumption figures for the various types of fridge/freezers. Easy to do some basic calcs and work out how long you need to drive for.

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Gday Terry,
My alternator is the standard Hitachi 60Amps, and the fridge is a Matson 65L. 5.5Amps / 65watts with 12v input.

So you reckon that just a standard isolator for the battery under the bonnet instead of the BC 1220? There are so many opinions, it is very hard to know which way to go. All I want is to get the best lifespan, charging, and use out of my batteries. I don't care how I do it, I just want it done properly..!

My next challenge is to find some photos if anyone has put a dual battery under the hood of a D22 and how they did it.

Cheers
T

I wont get into the debate about right and wrong way to wire up a second battery because i disagree with most internet theorist, but you should find a number of D22 garages (or maybe the slideshow) with dual battery set ups because there is quite a few people who have them

The main difference between d22 and D40 set up is depending on the size of the second battery it may fit under the bonnet in a D22, in a D40 they wont so if you check out both models you might decide if under the bonnet is best for you or maybe in the tub like those of us without under bonnet space.

Geez mate that's a bit spooky. I was just reading your reply to Palmaa221 about his dual battery install question.

I am going to have four batteries to charge simultaneously however off the alternator when driving, which is why I was looking at the Redarc 1220 in both the car and trailer...

If its not required in the car I won't put one in, but I need to make the decision by tomorrow as I'm running out of time to get it all done.

And yep, you are right about one thing. Trying to read all the posts on dual batteries is time consuming.!

Tony in Tas said:

Geez mate that's a bit spooky. I was just reading your reply to Palmaa221 about his dual battery install question.

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Don't hold that against me, I don't remember what I typed before lunch let alone what I typed in previous days or weeks

I have the tjm/piranha dual battery tray in my 04 nav $170 thereabouts simple one coffee install, The only downside if you like is the battery size 60 or 65 amp i think is in mine, But i can park the ute for 2 days and my 40 litre engel is still running, Was cold outside and only opened fridge a few times. But it does me i have a $120 redarc connecting the dual battery and a anderson plug going to the camper when connected

A question for someone with knowledge on this. Does the 2012 Navara with the 2.5 turbo use the can-bus system to control the alternator. This makes a difference when ordering a Redarc. If NOT Can-bus you can use the BCDC-1220 but if Can-bus controlled I will need to order a BCDC-1220-ign model.
Thanks

How will data link change the availability of charge rate for dual batteries?

gunning1987 said:

How will data link change the availability of charge rate for dual batteries?

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I'm guessing the can-bus system might detect the unsanctioned battery drain and unleash Hell's fury upon the user.